Mixtures comprising acrylonitrile polymers with polyacrylonitrile



United States Patent NHXTURES COMPRISENG ACRYLONITRILE POLY- MERS WITHPOLYACRYLONITRILE.

Harry W. Coover, Jr., and Joseph B. Dickey, Kingsport,

Tenn., assignors to Eastman Kodak Company, Rochester, N. Y., acorporation of New Jersey No Drawing. Application October 21, 1952,Serial No. 316,054

18 Claims. (Cl. 26032.6)

This invention relates to composite resinous compositions comprising amixture of acrylonitrile polymers and polyacrylonitrile.

This application is a continuation-in-part of our copending applicationSerial No. 164,854, filed May 27, 1950 of H. W. Coover, Jr. and JosephB. Dickey (now U. S. Patent 2,649,434, dated August 18, 1953).

It is known that polyacrylonitrile fibers can be spun which haveexcellent physical properties such as high strength, high stickingtemperatures and good resistance to shrinkage at elevated temperatures.However, such fibers show certain disadvantageous properties whichseverely limit their commercial use such as low moisture absorption andmore especially poor dyeability with most available dyes of thecellulose acetate, direct cotton, acid wool and vat type of dyes. For agreat many textile purposes, improved dyeability of polyacrylonitrilefibers or fibers produced from polymers containing a high percentage ofacrylonitrile would be highly desirable.

It is further known that greatly increased moisture absorption anddyeability of acrylonitrile fibers can be obtained by copolymerizingacrylonitrile with certain other unsaturated compounds whose polymersare shown to have good afiinity for various dyes. While this proceduredoes give polymeric products having improved dyeability, a seriousdrawback arises in certain instances in that the fiber produced show amaterially lower soften ing point, thus limiting their practical uses.Another procedure employed for the purpose of increasing dye aifinityfor polyacrylonitrile has been to mix the polyacrylonitrile, beforespinning, with other film-forming materials which are known to bereadily dyeable. However, it has been well established thatacrylonitrile polymers are incompatible with most other polymericmaterials. ,Out of many hundreds of synthetic polymers that have beentested, only a relatively small number of them have been foundsufliciently compatible. For example, it can be demonstrated thatmixtures of polyacrylonitrile with polyvinyl acetate, when dissolved inN,N-dimethyl formamide in proportions varying from to 50 percent byweight of the polyvinyl acetate and from 85 to 50 percent by weight ofthe polyacrylonitrile form grainy dopes which separate on standing intotwo liquid layers, and that fibers formed from such mixtures showsegmentation into their individual components along their horizontalaxes.

We have now found that stable, homogeneous solutions comprising twodifferent acrylonitrile polymers which do not separate into distinctlayers on standing, and from which fibers of good dyeability andexcellent physical properties can be spun, can be obtained by dissolvingin acrylonitrile solvents, individually or in inti- 2,776,270 PatentedJan. 1, 1957 vinyl esters, acrylates, acrylamides, citraconamides,itaconamides and their N-substituted derivatives.

It is, accordingly, an object of our invention to provide compositeresinous compositions comprising certain acrylonitrile polymersintimately admixed with polyacrylonitrile. Another object is to providea process for preparing these compositions. A further object is toprovide homogeneous and stable solutions of the compositions. A stillfurther object is to provide fibers prepared therefrom. Other objectswill become apparent hereinafter.

In accordance with our invention, we prepare the composite resinouscompositions of the invention by intimately mixing or by dissolving insuitable acrylonitrile polymer solvents such as dimethyl formamide,dimethyl acetamide, gamma-butyrolactone, ethylene carbonate, ethylenecyanohydrin, etc., in any individual order or in intimate admixture,from 5 to 95 parts by weight of polyacrylonitrile and from 95 to 5 partsby weight of an acrylonitrile polymer prepared by homopolymerizing from5 to 95 percent by weight of acrylonitrile in the presence of from 95 to5 percent by weight of a preformed live modifying homopolymer. Thepreformed live homopolymer is always polymerized until substantiallynone of its monomer remains in the polymerization mixture, then theacrylonitrile monomer is added thereto and the polymerization continued.However, all of the added acrylonitrile need not necessarily becompletely polymerized, since satisfactory products are also obtainedwhere the acrylonitrile polymerization is carried out to the extent thatpercent or more of the acrylonitrile is polymerized. The solutions ordopes obtained in the above-mentioned solvents are clear and homogeneousand do not separate into two layers on standing or during spinningoperations. Fibers can be spun from such solutions (dopes) by either thewet or dry spinning methods. The concentration of the polymers in thesolvent can vary widely from very low (less than 1%) to much higherconcentrations, but for efiicient operations the concentration isadvantageously from 5-20 percent. The dopes are stable over the usualtemperature range of operations for spinning.

The preformed polymers which are useful in practicing our invention canbe prepared by polymerizing monomers containing ethenoid unsaturationaccording to methods well known to the art.

itaconamides, and vinyl esters provide compositions showing especiallyuseful properties. The acrylamides have been found to be especiallyadvantageous when used according to our invention.

The acrylamides which can be advantageously used in our inventioncomprise those represented by the following general formula:

wherein R and R1 each represents a hydrogen atom or alkyl group, such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc. groups (e.g. an alkyl group of the formula CnHzn+1 wherein n represents a positiveinteger of from 1 to 4), and R2 represents a hydrogen atom or a methylgroup. Typical acrylamides include acrylamide, N-methylacrylamide,N-ethylacrylamide, N-isopropylacrylamide, N-n-butylacrylamide,methacrylamide, N- methylmethacrylamide, N-ethylmethacrylamide,N-isopropylmethacrylamide, N,N-dimethylacrylamide, N,N-diethylacrylamide, N,N-dimethylmethacrylamide, etc.

As ethenoid compounds we have found that acrylamides, acrylic esters,citraconamides,'

As acrylic esters, we can advantageously use those represented by thefollowing general formula:

wherein R3 represents an alkyl group, such as methyl, ethyl, n-propyl,isopropyl, n-butyl, isobutyl, etc groups (e. g. an alkyl group of theformula CnH2n+1 wherein n represents a positive integer from 1 to 4),and R4 represents a hydrogen atom, a methyl group, an acylamino groupwherein the acyl group is the acyl group of a saturated aliphaticcarboxylic acid containing from 2 to 4 carbon atoms, such as acetyl,propionyl, butyryl, isobutyryl, etc. groups, or a carbalkoxylamino groupwherein the alkoxyl group contains from 1 to 4 carbon atoms such asmethyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, etc. groups.Typical esters wherein R4 represents a hydrogen atom or a methyl groupinclude methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutylacrylate, methyl methacrylate, ethyl methacrylate, n-propylmethacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutylrnethacrylate, etc. Typical esters wherein R4 represents an acylaminogroup include, for example, methyl a-acetaminoacrylate, ethyla-acetaminoacrylate, n-propyl a-acetaminoacrylate, isopropyla-acetaminoacrylate n-butyl a-acetaminoacrylate, methyla-propionaminoacrylate, ethyl u-propionaminoacrylate, n-butyla-propionaminoacrylate, methyl u-n-butyraminoacrylate, ethylot-n-butyraminoacrylate, isobutyl a-n-butyraminoacrylate, methyla-isobutyraminoacrylate, ethyl a-isobutyraminoacrylate, n-propyla-isobutyramin oacrylate, isobutyl a-isobutyraminoacrylate, etc. Theacrylic esters wherein R4 represents an acylarnino group can be preparedaccording to the general method described in the copending applicationSerial No. 87,356, filed April 13, 1949, of H. W. Coover, Jr. and JosephB. Dickey (now U. S. Patent 2,548,518, dated April 10, 1951). Theprocess described in that application comprises reacting an alkali metalsalt of an a-acylaminoacrylic ester with a dialkyl sulfate. The alkalimetals useful for this process comprise those set forth in Serial No.87,356 and also the alkali metal salts of the u-acylaminoacrylic estersdescribed in the copending application Serial No. 132,216, filedDecember 9, 1949, of H. W. Coover, Jr. and Joseph B. Dickey (now U. S.Patent 2,622,074, dated December 16, 1952).

The acrylic esters wherein R4 represents a carbalkoxylamino group can beprepared according to the method described in application Serial No.132,217, filed Decemher 9, 1949, of Joseph B. Dickey and H. W. Coover,Jr. (now U. S. Patent 2,563,776, dated August 7, 1951). Typical esterswherein R4 represents a carbalkoxylamino group include methylwcarbomethoxyaminoacrylate, ethyl a-carbomethoxyaminoacrylate, isobutyla-carbomethoxyaminoacrylate, methyl a-carbethoxyaminoacrylate, n-propyla-carbethoxyaminoacrylate, isobutyl a-carbethoxyaminominoacrylate,methyl a-carbopropoxyaminoacrylate, ethyl et-carbopropoxyaminoacrylate,-isopropyl OL-Cfil'bO- propoxyaminoacrylate, n-butyla-carbopropoxyaminoac rylate, methyl u-carbisopropoxyaminoacrylate,isobutyl otcarbisopropoxyaminoacrylate, methyla-carbobutoxyaminoacrylate, n-propyl a-carbobutoxyaminoacrylate, methyla-carbisobutoxyaminoacrylate, ethyl a-carbisobutoxyaminoacrylate,n-butyl e-carbisobutoxyaminoacrylate, etc.

As itaconamides, we can advantageously use those represented by thefollowing general formula:

wherein R5, R6, R7, and R8 each represents a hydrogen atom, a methylgroup, an ethyl group, etc- Typical itaconamides include itaconamide,N-methyl itaconamide, N-ethyl itaconamide, N,N-dimethyl itaconamide,N,N'- dimethyl itaconamide, etc.

As citraconamides, we can advantageously use those represented by thefollowing general formula:

0 R5 II wherein R5, R6, R7, and Rs have the values given above. Typicalcitraconamides include citraconamide, N-methyl citraconamide, N-ethylcitraconamide, N,N'-dimethyl citraconamide, N,N'-diethyl citraconamide,etc.

As vinyl esters, we can advantageously employ those represented by thefollowing general formula:

wherein R9 represents a hydrogen atom or an alkyl group, such as methyl,ethyl, n-propyl, isopropyl, etc. groups (e. g. an alkyl group containingfrom 1 to 3 carbon atoms).

The polymerization can be accelerated by the use of a well-knownpolymerization catalyst. Such catalysts are commonly used in the art ofpolymerization, and our invention is not to be limited to any particularcatalyst materiaI. Catalysts which have been found to be especiallyuseful comprise the peroxide polymerization catalysts, such as theorganic peroxides (e. g. benzoyl peroxide, acetyl peroxide, acetylbenzoyl peroxide, lauryl peroxide, oleoyl peroxide, triacetone peroxide,urea peroxide, t-butyl hydroperoxide, alkyl percarbonates, etc.),hydrogen peroxide, perborates (e. g. alkali metal perborates, such asthose of sodium and potassium, etc.), persulfates (e. g. alkali metalammonium persulfate, etc. Other catalysts such as the ketazines, azines,etc. can be used. The quantity of catalyst used can be varied, dependingon the monomer, amount of diluent, etc. Sufficient catalyst can be usedto homopolymerize the ethenoid monomer selected from those representedby the above general formulas and the monomeric acrylonitrile, or anamount of catalyst sufficient to polymerize only the ethenoid monomercan be used, and additional catalyst can be added with the acrylonitrilemonomer to complete the polymerization. The catalyst added along withacrylonitrile may be the same catalyst that was used to polymerize theother ethenoid monomer. We have found that it is especially advantageousto use an amount of catalyst sufficient to polymerize only the firstmonomer, and then upon addition of the acrylonitrile to add a furtheramount of catalyst at that time. This procedure provides a readier meansfor regulating the molecular weight distribution of the polymercomposition.

The temperature at which the process of our invention can be carried outvary from ordinary room temperature to the reflux temperature of thereaction mixture. Generally, a temperature of from 25 to C. issulficient.

If desired, emulsifying agents can be added to the reac tion mixture todistribute uniformly the reactants throughout the reaction medium.Typical emulsifying agents include the alkali metal salts of certainalkyl acid sulfates (e. g. sodium lauryl sulfate), alkali metal salts ofaromatic sulfonic acids (sodium isobutylnaphthalenesulfonate), alkalimetal or amine addition salts of sulfosuccinic acid esters, alkali metalsalts of fatty acids containing from 12 to 20 carbon atoms, sulfonatedfatty acid amides, alkali metal salts of alkane sulfonic acids,sulfonated ethers (e. g. aryloxy polyalkylene ether sulfonates, such asTriton 720), etc.

The polymerization can be carried out in the presence of chainregulators, such as hexyl, octyl, lauryl, dodecyl, myristyl mercaptans,etc., which impart improved solubility properties to the polymercomposition. If desired,

reducing agent such as alkali metal bisulfites (e. g. potassium, sodium,etc. bisulfites) can be added to reduce the time required for thepolymerization to be elfected.

The following examples will serve to illustrate further the mannerwhereby we practice our invention.

Example 1 9.7 g. of vinyl acetate were suspended in 100 cc. of distilledwater along with 0.1 g. of ammonium persulfate, 0.1 g. of sodiumbisulfite, and 1.0 g. of an aryloxy polyalkylene sulfonated ether typeof emulsifying agent. The resulting emulsion was allowed to polymerizefor 16 hours at 50 C. and then cooled down to room temperature. Asolution of 0.5 g. of acrylonitrile, 0.01 g. of ammonium pesulfate, and0.01 g. of sodium bisulfite in cc. of water was added and thepolymerization completed by tumbling at 50 C. for 8 hours. The emulsionwas broken by the addition of a concentrated salt solution, and theprecipitated polymer was filtered, washed, and dried. On analysis, thepolymer composition was found to contain 95 percent by weight of vinylacetate.

Fibers obtained from a mechanical mixture containing 30 percent byweight of the polymer obtained and 70 percent by weight ofpolyacrylonitrile, by extruding a solution of the mixture inN,N-dimethylformamide into a precipitating bath, had a tenacity of 3.4g, per denier, an extensibility of 20 percent, a sticking temperature of195 C., and shrank 9 percent in boiling water.

Example 2 2.0 g. of N-methylmethacrylamide were dissolved in 80 cc. ofwater along with 0.2 g. of potassium persulfate and 0.02 g. of sodiumbisulfite. The solution was allowed to polymerize for sixteen hours at25 C. There were then added 8.0 g. of acrylonitrile, 0.1 g. of potassiumpersulfate and 0.1 g. of sodium bisulfite, and the mixture was allowedto polymerize for eight hours at 25 C. The polymer product was thenseparated from the reaction mixture by filtration, yielding 9.2 g. Onanalysis the polymer was found to contain 21 percent by weight ofN-methylmethacrylamide.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and fihns of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 50 partspolyacrylonitrile and 50 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.1 g. per denier,an extensibility of 20 percent, a sticking temperature of 210 C., andshrank only 6 percent in boiling water.

Example 3 2.0 g. of N-methylacrylamide were dissolved in 100 cc. ofwater containing 0.04 g. of potassium persulfate. The solution washeated at 50 C. for sixteeen hours, and the solution cooled to roomtemperature. There were then added 8.0 g. of acrylonitrile, 0.1 g. ofpotassium persulfate and 0.1 g. of sodium bisulfite. The reactionmixture was then allowed to stand at 25 C. for sixteen hours. Theprecipitated polymer weighed 8.5 g. and contained 20 percent by weightof N-methylacrylamide.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 5 partspolyacrylonitrile and 95 parts of the above polymer, and extruding thesolution into a precipitating bath, had a tenacity of 3.3 g. per denier,an extensibility of 19 percent and a sticking temperature of 225 C.

- Example 4 I 2.0 g. of vinyl acetate were suspended in 18 cc. of wateralong with 0.02 g. of ammonium persulfate, 0.02 g. of sodium bisulfite,and 1.1 g. of an aryloxy polyalkylene sulfonated ether type ofemulsifying agent. The resulting emulsion was allowed to polymerize forsixteen hours at 50 C., then cooled down to room temperature and addedto a dispersion containing 8.0 g. of acrylonitrile, 1.0 g. of ammoniumpersulfate, 0.1 g. of sodium bisulfite, and 2.0 g. of an aryloxypolyalkylene sulfonated ether (Triton 720) in 50 cc. of water. Aftertumbling the reaction mixture at 50 C. for two hours, the polymerproduct was precipitated by the addition of an aqueous solution ofsodium chloride to give 9.7 g. of polymer product containing 20 percentby weight of vinyl acetate.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 10 partspolyacrylonitrile and 90 parts of the above polymer and extruding thesolution into a. pre cipitating bath, had a tenacity of 3.2 g. perdenier, an extensibility of 21 percent and a sticking temperature of 210C.

Example 5 2.0 g. of methacrylamide were dissolved in 50 cc. of watercontaining 0.05 g. of ammonium persulfate. The resulting solution washeated at 50 C. for sixteen hours, cooled to room temperature, and amixture containing 8.0 g. of acrylonitrile, 0.1 g. of ammoniumpersulfate, and 0.1 g. of sodium bisulfite was added. The reactionmixture was allowed to stand at 25 C. for sixteen hours. Theprecipitated polymer weighed 9.3 g. and contained 19 percent by weightof methacrylamide by analysis.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 20 partspolyacrylonitrile and parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3 g. per denier,an extensibility of 21 percent and a sticking temperature of 215 C.

Example 6 4.0 g. of vinyl acetate were suspended in 40 cc. of watercontaining 0.04 g, of ammonium persulfate, 0.04 g. of sodium bisulfite,and 2.2 g. of an aryloxy polyalkylene sulfonated ether type ofemulsifying agent. The resulting emulsion was allowed to polymerize forsixteen hours at 50 C., then cooled to room temperature and a dispersioncontaining 6.0 g. of acrylonitrile, 0.1 g. of potassium persulfate, 0.1g. of sodium bisulfite, and 2.0 g. of an aryloxy polyalkylene sulfonatedether type of emulsifying agent in 50 cc. of water was added. Thereaction mixture was tumbled for two hours at 50 C. There were thusobtained 9.4 g. of polymer product containing 43 percent by weight ofvinyl acetate.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Exampl 7 sion was allowed to polymerize for 16 hours at 50 C.,

the reaction mixture for 4 hours at 50 C. there were obtained 9.7 g. ofpolymer containing 83 percent by weight of vinyl acetate.

The polymers can be mixed with polyacryl'onitri-le in all proportionsand dissolved to give stable solutions Which do not separate intodistinct layers on standing and from which fibers and films ofhomogeneous character can be spun, extruded or cast.

Example 8 2.0 g. of citraconamide, 0.05 g. of potassium persulfate and 1cc. of 7-ethyl-2-methylundecan-4-sulfonic acid sodium salt (Tergitol No.4) were added to cc. of water. The resulting emulsion was then tumbledat 50 C. for 12 hours, at the end of which time 8.0 g. of acrylonitrileand 0.1 g. of potassium persulfate in 70 cc. of water were added. Thereaction mixture was then tumbled for an additional 12 hours at 50 C.The resulting polymer was obtained in an 88 percent yield and contained18 percent by weight of citraconamide by analysis. It was soluble ineither N,N-dimethylformamide or N,N-dimethylacetamide.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 70 partspolyacrylonitrile and 30 parts of the above polymer and extruding thesolution into a precipitatlng bath, had a tenacity of 3.3 g. per denier,an extensibility of 22 percent and a sticking temperature of 220 C.

Example 9 3.0 g. of itaconamidc, 0.1 g. of ammonium persulfate, 0.1 g,of sodium bisulfite, and 1.0 g. of an aryloxy polyalkylene sulfonatedether type of emulsifying agent were added to 50 cc. of distilled water.The resulting emulsion was then heated for 12 hours at C. with tumbling.A solution of 17.0 g. of acrylonitrile, 0.2 g. of ammonium persulfateand 0.2 g. of sodium bisulfite in cc. of distilled water was then added.The reaction mixture was then heated for an additional 8 hours at 35 C.The resulting polymer was obtained in an 89 percent yield and contained14 percent by weight of itaconamide by analysis.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast,

Fibers obtained from a solution of a mechanical mixture of partspolyacrylonitrile and 40 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.4 g. per denier,an extensibility of 22 percent and a sticking temperature of 215 C.

Example 10 9.5 g. of N-methylacrylamide were dissolved in 50 cc. ofwater containing .1 g. of ammonium persulfate and .1 g. of sodiumbisulfite. The resulting solution was tumbled for 8 hours at 35 C. andafter cooling to room temperature, .5 g. of acrylonitrile and .05 g. ofsodium bisulfite were added and the polymerization was completed byheating at 35 C. for an additional six hours.

The polymer was isolated by pouring the resulting emulsion into acetone.The precipitated polymer was filtered,-

washed with acetone, and dried.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Example 11 9 g. of methylacrylate were suspended in cc. of watercontaining 0.1 g. of percent hydrogen peroxide and l g. of an aryloxypolyalkylene sulfonated ether type of emulsifying agent. The resultingemulsion was tumbled for 14 hours at 50 C. and after cooling to roomtemperature, 1 g. of acrylonitrile and 0.05 g. of 90 percent hydrogenperoxide solution Were added. After tumbling for an additional 12 hoursat 50 C., the polymerization was substantially complete. The resultingpolymer contained 9 percent methylacrylate by analysis and was solublein such solvents as N,N-dimethylformamide and N,N-dimethylacetamide,etc.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and fromwhich fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 90 partspolyacrylonitrile and 10 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 3.1 g. per denier,an extensibility of 20 percent and a sticking temperature of 205 C.

Example 12 20 g. of vinyl acetate were suspended in cc. of water alongwith 0.2 g. of ammonium persulfate, 0.2 g. of sodium bisulfite, and 4cc. of 7-ethyl-2-rnethylundecan-4- sulfonic acid sodium salt (TergitolNo. 4). The resulting emulsion was heated for 16 hours at 50 C., andafter cooling to room temperature, there were added 10 g. ofacrylonitrile, 0.1 g. of ammonium persulfate, and 0.1 g. of sodiumbisulfite. The reaction mixture was heated for an additional 12 hours at35 C. There was thus obtained a polymer in 91 percent yield whichcontained 29 percent acrylonitrile by analysis.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Fibers obtained from a solution of a mechanical mixture of 60 partspolyacrylonitrile and 40 parts of the above polymer and extruding thesolution into a precipitating bath, had a tenacity of 2.9 g. per denier,an extensibility of 23 percent and a sticking temperature of 200 C.

Example 13 10 g. of N-methylacrylamide were dissolved in 50 cc. of watercontaining 0.1 g. of potassium persulfa-te and 0.1 g. of sodiumbisulfite. The solution was then heated for 12 hours at 35 C., at theend of which time polymerization seemed to be complete. There were thenadded 2.0 g. of acrylonitrile, 0.01 g. of potassium persulfate and 0.01g. of sodium bisulfite, and the reaction mixture was heated for anadditional 8 hours at 35 C. The polymer was precipitated by the additionof acetone and was obtained in an 86 percent yield. It contained 16percent acrylonitrile by analysis.

Fibers obtained from a mixture of the polymer obtained in the aboveexample and polyacrylonitrile contained 20 percent N-methylacrylamideand had a tenacity of 3.2 g. per denier, an extensibility of 21 percent,a sticking temperature of 200 C., and shrank 10 percent in boilingwater. The fibers had an excellent affinity for acetate, direct vat, andacid dyes.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from 9 which fibers and films of homogeneouscharacter can be spun, extruded or cast.

Example 14 12 g. of methyl u-acetaminoacrylate were dissolved in 50 cc.of distilled water containing 0.1 g. of ammonium persulfate. 16 hours at35 C., at the end of which time polymerization appeared to be complete.There Were added tothe cooled mixture 2.0 g. of acrylonitrile, 0.02 g.of ammonium persulfate, and 0.02 g. of sodium bisulfite. The reactionmixture was then heated for an additional 12 hours at 35 'C., and theresulting polymer was coagulated by the addition of acetone. The polymercontained 14 percent acrylonitrile by analysis.

Fibers obtained from a mixture of the polymer obtained in the aboveexample and polyacrylonitrile contained 30 percent methyla-ace-taminoacrylate and had a tenacity of 3.5 g. per denier, a stickingtemperature of 225 C., 5.3 percent moisture absorption at 65 percentrelative humidity, and shrank 11 percent in boiling water. The fibershad excellent aflinity for acetate, direct, vat, and acid dyes.

Example 15 1.0 g. of N-isopropylmethacrylamide was dissolved in 50 cc.of acetonitrile containing 0.05 g. of benzoyl peroxide. The solution washeated for 16 hours at 65 C., and after cooling to room temperature,there were added 9.0 g. of acrylonitrile and 0.1 g. of benzoyl peroxide.The reaction mixture was then heated for an additional 16 hours at 65 C.The resulting polymer was obtained in an 85 percent yield and contained9 percent N-isopropylmethac-rylam-ide. 1

The polymers can be mixed with poly acrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded or cast.

. Example 16 3.0 g. of methyl a-carbethoxyaminoacrylate were dissolvedin 70 cc. of water containing 0.05 g. of potassium persulfate and 0.05g. of sodium bisulfite. The mixture was then held for 8 hours at roomtemperature at the end of which time polymerization appeared to becomplete. There were then added 7.0 g. of acrylonitrile, 0.1 g. ofpotassium persulfate, and 0.1 g. of sodium bisulfite, and the reactionmixture was allowed to stand for an additional 8 hours. The polymer wasobtained in an 85 percent yield and contained 32 percent methylu-carbethoxyaminoacrylate by analysis.

The polymers can be mixed with polyacrylonitrile in all proportions anddissolved to give stable solutions which do not separate into distinctlayers on standing and from which fibers and films of homogeneouscharacter can be spun, extruded, or cast.

The mixtures of the invention which have a combined acrylonitrilecontent by weight of from 60 to 95 percent, the remainder of thecomposite composition being made up of other of the mentioned componentsof the invention, are particularly useful for preparing fiber-formingmaterials. However the above compositions, together with the compositecompositions which have a combined acrylonitrile content by weight offrom to 60 percent, the remainder of the composite composition in eachcase being made up of other of the mentioned components of theinvention, can all be made up into solutions or dopes in the mentionedsolvents, with or without fillers, pigments, dyes, plasticizers, etc.,as desired, and the dopes coated on a smooth surface to give flexibleand tough films and sheet materials which are useful for photographicfilm support and other-purposes.

Other solvents which can be used for the preparation of fibers andcoating compositions for the new polymer mixtures of our inventioninclude'ethylene carbamate,

The reaction mixture was then heated for N methyl-2-pyrrolidone,N,N-dimethylmethoxyacetamide, dimethyl cyanamide, N,N-dimethylcyanoacetamide, N,N- dimethyl-fl-cyanopropionamide, glycolonitrile(formaldehyde cyanohydrin), malononitrile, dimethylsulfoxide, dimethylsulfone, tetra'methylene sulfone, tetramethylene sulfoxide, Nformylpyrrolidine, N formylmorpholine, N,N'-tetramethylenemethanephosphonamide, and the like.

In addition to the above-described mixtures, we have found that theacrylonitrile polymers containing alkenyl carbonamides can also be mixedwith each other or with other acrylonitrile copolymers containing atleast percent by weight of acrylonitrile and 15 percent by weight ofanother monoethylenically unsaturated, polymerizable compound containinga CH=C group or a CH2=C group, to give generally similar stablehomogeneous solutions.

What we claim is:

1. A resinous composition comprising a mixture of from 5 to parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueous dispersion of monomer selected fromthe group consisting of those represented by the following'generalformulas:

and

wherein R and R1 each represents a member selected from the groupconsisting of a hydrogen atom and an alkyl group containing from 1 to 4carbon atoms, R2 represents a member selected from the group consistingof a hydrogen atom and a methyl group, R3 represents an alkyl groupvcontaining from 1 to 4 carbon atoms, R4 represents a member selectedfrom the group consisting of a hydrogen atom, a methyl group, anacylamino group, wherein the acyl group is the acyl group of a saturatedaliphatic carboxylic acid containing from 2 to 4 carbon atoms and acarbalkoxylamino group wherein the alkoxyl group contains from 1 to 4carbon atoms, R5, R6, R7 and Rs each represents a member selected fromthe group consisting of a hydrogen atom, a methyl group and an ethylgroup, and R9 represents a member selected from the group consisting ofa hydrogen atom and an alkyl group containing from 1 to 3 carbon atoms,until the monomer has substantially completely homopolymerized, addingto the polymerization reaction mixture containing said homopolymerizedmonomer from 5 to 95 percent by weight of acrylonitrile, based on thecombined weights of the other monomer and acrylonitrile, and heating thereaction mixture until the acrylonitrile has substantially polymerized.

2'. A resinous composition comprising a mixture of from to 95 parts byweightof polyacrylonitrile and from 95 m5 parts by weight ofapreformed-acrylonitrile polymer obtained by heatingin-the presence of apolymerization catalyst an aqueous dispersion ofan acrylamideselected-from-those represented by the following general formula:

wherein R represents an alkyl group containing from 1 to 4 carbon atoms,untilthe monomer hassubstantially completely homopolymerized, adding tothe polymerization reaction mixture containing said homopolymerizedmonomer from 5 to 95 percent'by weight of acrylonitrile, based on thecombined weights of the acrylamide and acrylonitrile, and heating thereaction mixture until the acrylonitrile has polymerized to yield amodified polymer. containing 5 to 95 percent by'weightof acrylonitrile.

3. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst-an aqueous dispersion of a methacrylamideselected from those represented by the following general formula:

wherein R represents an alkyl group containing from 1 to 4 carbon atoms,until the monomer has substantially completely homopolymerized, addingto the polymerization reaction mixture containing said homopolymerizedmonomer from 5 to 95 percent by weight of acrylonitrile, based on thecombined weights of the methacrylamide and acrylonitrile, and heatingthe reaction mixture until the acrylonitrile has polymerized to yield amodified polymer containing 5 to 95 percent by weight of acrylonitrile.

4. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueous dispersion of a vinyl ester selectedfrom those represented by the following general formula:

wherein R9 represents an alkyl group containing from 1 to 3 carbonatoms, until the monomer has substantially completely homopolymerized,adding to the polymerization reaction mixture containing saidhomopolymerized monomer from 5 to 95 percent by weight of acrylonitrile,based on the combined weights of vinyl ester and acrylonitrile, andheating the reaction mixture until the acrylonitrile has polymerized toyield a modified polymer containing 5 to 95 percent by weight ofacrylonitrile.

5. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueous dispersion of N- methylacrylamideuntil homopolymerization is substantially complete, adding to thepolymerization reaction mixture containing the homopolymerized monomerfrom 5 to 95 percent by weight of acrylonitrile, based on the combinedweights of N-methylacrylamide and acrylonitrile, and heating thereaction mixture until the acrylonitrile has substantially polymerized.

6. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueousdispersion ofN-isopropylmethacrylamide until homopolymerization is substan:.

tially complete, adding to the polymerization reaction mixturecontaining the homopolymerized monomer from 5 to percent by weight ofacrylonitrile, based on the combined weights ofN-isopropylmethacrylamide and acrylonitrile, and heating the reactionmixture until the acrylonitrile has substantially polymerized.

7. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueous dispersion of N,N-dimethylacrylamideuntile homopolymerization is substantially complete, adding to thepolymerization reaction mixture containing the homopolymerized monomerfrom 5 to 95 percent by weight of acrylonitrile, based on the combinedweights of N,N-dimethylacrylamide and acrylonitrile, and heating thereaction mixture until the acrylonitrile has substantially polymerized.

8. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerization catalyst an aqueous dispersion of methacrylamide untilhomopolymerization is substantially complete, adding to thepolymerization reaction mixturecontaining the homopolymerized monomerfrom 5 to 95 percent by weight of acrylonitrile, based on the combinedweights of methacrylamide and acrylonitrile, and heating the reactionmixture until the acrylonitrlie has substantially polymerized.

9. A resinous composition comprising a mixture of from 5 to 95 parts byweight of polyacrylonitrile and from 95 to 5 parts by weight of apreformed acrylonitrile polymer obtained by heating in the presence of apolymerizationcatalyst an aqueous dispersion of vinyl acetate untilhomopolymerization is substantially complete, adding to thepolymerization mixture containing the homopolymerized monomer from 5 to95 percent by weight of acrylonitrile, based on the combined weights ofvinyl acetate and acrylonitrile, and heating the reaction mixture untilthe acrylonitrile has substantially polymerized.

10. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of a monomerselected from the group consisting of those represented by the followinggeneral formulas:

13 V r wherein R and R1 each represents a member selected from the groupconsisting of a hydrogen atom and an alkyl group containing from 1 to 4carbon atoms, R2 represents a member selected from the group consistingof a hydrogen atom and a methyl group, R3 represents an alkyl groupcontaining from 1 to 4 carbon atoms, R4 represents a member selectedfrom the group consisting of a hydrogen atom, a methyl group, anacylamino group, wherein the acyl group is the acyl group of a saturatedaliphatic carboxylic acid containing from 2 to 4 carbon atoms and acarbalkoxylamino group wherein the alkoxyl group contains from 1 to 4carbon atoms, R5, R6, R7 and Rs each represents a member selected fromthe group consisting of a hydrogen atom, a methyl group and an ethylgroup, and R9 represents a member selected from the group consisting ofa hydrogen atom and an alkyl group containing from 1 to 3 carbon atoms,until the monomer has substantially completely homopolymerized, addingto the polymerization reaction mixture containing said homopolymerizedmonomer from to 95 percent by weight of acrylonitrile, based on thecombined weights of the other monomer and acrylonitrile, and heating thereaction mixture until the acrylonitrile has polymerized to yield aproduct containing 5 to 95 percent by weight of acrylonitrile, in asolvent selected from the group consisting of dimethyl formamide,dimethyl acetamide, gamma-butyrolactone, ethylene carbonate and ethylenecyanohydrin.

11. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of anacrylamide selected from those represented by the following generalformula:

wherein R represents an alkyl group containing from 1 to 4 carbon atoms,until the monomer has substantially completely homopolymerized, addingto the polymerization mixture containing said homopolymerized monomerfrom 5 to 95 percent by Weight of acrylonitrile, based on the combinedweights of the acrylamide and acrylonitrile, and heating the reactionmixture until the acrylonitrile has substantially polymerized, indimethyl formamide.

12. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of amethacrylamide selected from those represented by the following generalformula:

wherein R represents an alkyl group containing from 1 to 4 carbon atoms,until the monomer has substantially completely homopolymerized, addingto the polymerization reaction mixture containing said homopolymerizedmonomer from 5 to 95 percent by weight of acrylonitrile, based on thecombined weights of the methacrylamide and acrylonitrile, and heatingthe reaction mixture until the acrylonitrile has substantiallypolymerized, in dimethyl formamide.

13. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of a 14,vinyl ester selected from those represented by the follow ing generalformula:

wherein R9 represents an alkyl group containing from 1 to 3 carbonatoms, until the monomer has substantially completely homopolymerized,adding to the polymerization mixture containing said homopolymerizedmonomer from 5 to percent by weight of acrylonitrile, based on thecombined weights of vinyl ester and acrylonitrile, and heating thereaction mixture until the acrylonitrile has substantially polymerized,in dimethyl formamide.

14. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of N-methylacrylamide until homopolymerization is substantially complete,adding to the polymerization mixture containing the homopolymerizedmonomer from 5 to 95 percent by weight of acrylonitrile, based on thecombined weights of N-methylacrylamide and acrylonitrile, and heatingthe reaction mixture until the acrylonitrile has substantiallypolymerized, in dimethyl formamide.

15. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of N-isopropylmethacrylamide until homopolymerization is substantiallycomplete, adding to the polymerization mixture containing thehomopolymerized monomer from 5 to 95 percent by weight of acrylonitrile,based on the combined weights of N-isopropylmethacrylamide andacrylonitrile, and heating the reaction mixture until the acrylonitrilehas substantially polymerized, in dimethyl formamide.

16. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion ofN,N-dimethylacrylamide until homopolymerization is substantiallycomplete, adding to the polymerization mixture containing thehomopolymerized monomer from 5 to 95 percent by Weight of acrylonitrile,based on the combined weights of N,N-dimethylacrylamide andacrylonitrile, and heating the reaction mixture until the acrylonitrilehas substantially polymerized, in dimethyl formamide.

17. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyacrylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion ofmethacrylamide until homopolymerization is subtantially complete, addingto the polymerization mixture containing the homopolymerized monomerfrom 5 to 95 percent by weight of acrylonitrile, based on the combinedweights of methacrylamide and acrylonitrile, and heating the reactionmixture until the acrylonitrile has substantially polymerized, indimethyl formamide.

18. A solution of a resinous composition comprising a mixture of from 5to 95 parts by weight of polyaerylonitrile and from 95 to 5 parts byweight of a preformed acrylonitrile polymer obtained by heating in thepresence of a polymerization catalyst an aqueous dispersion of vinylacetate until homopolymerization is substantially complete, adding tothe polymerization mixture containing the homopolymerized monomer from 5to 95 percent by weight of acrylonitrile, based on the combined weightsof vinyl acetate and acrylonitrile, and heating the reaction mixtureuntil the acrylonitrile has substantially polymerized, in dimethylformamide.

(References on following page) R f eHceSTCiQ Q n hQ o is p t n UNITEDSTATES PATENT-S Gordon et a1 Jan. 12, 1937 Fikentscher et a1 July 12,1938 Strain Oct. 11, 1938 Jacobson et a1 Feb. 16, 1943 13 Kropa Aug. 5,1947 Stanip e t a1. Oct. 16, 195.1 Coovep et a1. Mar. 11, 1952 Coover eta1. Dec. 2, 1952 Coover et a1. Aug. 18,1953 Coover et a1. Oct. 27, 1953Chaney et a1 Aug. 31, 1954

1. A RESINOUS COMPOSITION COMPRISING A MIXTURE OF FROM 5 TO 95 PARTS BYWEIGHT OF POLYACRYLONITRILE AND FROM 95 TO 5 PARTS BY WEIGHT OF APREFORMED ACRYLONITRILE POLYMER OBTAINED BY HEATING IN THE PRESENCE OF APOLYMERIZATION CATALYST AN AQUEOUS DISPERSION OF MONOMER SELECTED FROMTHE GROUP CONSISTING OF THOSE REPRESENTED BY THE FOLLOWING GENERALFORMULAS: